What does DTC's 17536 & 17538 long term fuel trim lean...
03-25-2003, 12:16 PM
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What does DTC's 17536 & 17538 long term fuel trim lean...
mean?
I know that it is caused by a bad MAF most of the time. What I want to know is what does the code mean.
Is the fuel trim outside of its possible range?
Eric Fletcher what are your thoughts?
I know that it is caused by a bad MAF most of the time. What I want to know is what does the code mean.
Is the fuel trim outside of its possible range?
Eric Fletcher what are your thoughts?
03-25-2003, 12:22 PM
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Re: What does DTC's 17536 & 17538 long term fuel trim lean...
As I understand it, the car measures immediate (i.e., short term) fuel trim based on the difference in O2 readings from the two sensors. It uses these values in a running average to calculate the long term fuel trim.
The calculated value is then used to adjust the air/fuel mixture (mostly at idle, part throttle, since WOT relies more on the preprogrammed maps). If the calculated long term fuel trim gets too far outside of its normal range (+/- 10, I think), it sets a DTC.
If you had a problem with one of the O2 sensors, you might see the fault only on one bank, but both probably points to a MAF issue.
-Dave Pramanik
The calculated value is then used to adjust the air/fuel mixture (mostly at idle, part throttle, since WOT relies more on the preprogrammed maps). If the calculated long term fuel trim gets too far outside of its normal range (+/- 10, I think), it sets a DTC.
If you had a problem with one of the O2 sensors, you might see the fault only on one bank, but both probably points to a MAF issue.
-Dave Pramanik
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